Researchers have long known that humans generally prefer (all else being equal) taller leaders. Taller people are more likely to be elected to office, become CEO, get paid more, be considered more authoritative, etc. But why would that be? It seems kind of silly — what does height have to do with ability to lead?
Since this is widespread it likely has some genetic basis, but what in the world would be adaptive about being biased toward following the taller of those who try to lead? Unless there really were a correlation between height and ability to lead, then such an innate preference would just weaken our ability to choose good leaders, causing us to discount whatever truly useful data we had about the person’s intelligence, temperament, skills of persuasion, etc. There must be some context in which an inclination to follow the lead of tall people makes good sense, or the genetic basis for it would have been extinguished.
A possible answer hit me today. Of course, in order to talk about an evolutionary explanation for anything, we must imagine humans hundreds of thousands of years ago, in conditions very different from those of modern life. So yes, imagine yourself way back when — still, why prefer what the tall guy suggests? What sense would that make?
Probably none if you are an adult. But if you are a five-year-old kid playing with other kids in your clan, and something out of the ordinary happens, then you would probably do quite well to follow the lead of the older kids in the group. They know the most about the environment. They have absorbed the most wisdom from their parents. They likely have the best impulse control and sense of responsibility to the group.
And of course those older kids are very likely the tallest kids. Genes seldom travelled long distances in those days, so genes for height would have been pretty similar within a clan. So height among kids was surely an excellent proxy for age (better even than it is today), and hence for wisdom. So, perhaps kids with a built-in heuristic that told them to follow the lead of the tall survived to reproduce a little better than those without it, passing the genes responsible for the preference on to us. The fact that adults exhibit the bias could just be a side effect. Since people did not live as long back then, there would have been less downside to being influenced by irrelevant factors as an adult.
Or hmmm, perhaps the fact that the group agreed on a leader was generally more important than that you chose the best one — the group had to stick together rather than splinter over leadership. In that case height, while being completely uncorrelated with adult leadership skills, serves as an unambiguous criterion by which social cohesion is enhanced: we agree on Fred as our leader because he is the tallest. Being tallest is really only intrinsically relevant to leadership when we are children, but as adults we need some way to choose between otherwise-equal candidates, and what the hell — height will serve.
I have no idea how we could test this hypothesis….
A recent study suggests that we consider men with beards more authoritative, too. These days lots of grown men don’t have beards, but back then if you were an adult male, you generally had a beard, so this seems like another case of an age indicator conveying authority.
[Note: I’m skeptical about the study’s attempt to say anything about the attractiveness of bearded males, since they specifically used expressions of anger.]